Instrumentation for observation of induced seismicity

Instrumentation for observations of seismicity and ground acceleration near artificial reservoirs is evolving rapidly at the present time. Data recorded between 1936 and 1970, generally with only 1–3 seismograph stations, has established that the impounding of a large reservoir may lead to increased seismicity. Occasionally, shallow earthquakes in excess of magnitude 6 have occurred with resulting damage to surface structures and loss of life. Conditions leading to severe earthquakes have not been established but the pattern of enhanced seismicity as the reservoir level rises indicates that it is possible to predict when a dangerous level of earthquake rise is approaching. Increased use is now being made of larger arrays of detectors together with telemetry, storage of data on magnetic tape and even digital recording in the field. Future developments include complete digital recording of a broad range of instrumentation and detection and control of sampling rates by on-line micro-computers. As our instrumental sophistication increases and the relevant parameters for precursor activity are established it would appear that earthquake prediction near reservoirs is a possibility.